never heard of PT barnums penetrating catalyzer or whatever, but Tri flow is another product that works well in situations like this. Can be bought in most hardware stores. If you don't have a socket or wrenches that fit the bolt properly(it could be metric or SAE) then the bolt head is stripped beyond what these can do and your next best bet is vice grips. It may be cheaper to grind/hacksaw the bolt off and replace it than buy specialty tools, if this is possible without damaging the frame. assuming the seat post is a common size and is a cheap/generic one it may be really easy to replace for really cheap, if you were to say grind into it with an angle grinder....just saying.